Nematicity dynamics in the charge-density-wave phase of a cuprate superconductor

Understanding the interplay between charge, nematic, and structural ordering tendencies in cuprate superconductors is critical to unraveling their complex phase diagram. Using pump-probe time-resolved resonant x-ray scattering on the (0 0 1) Bragg peak at the Cu L3 and oxygen K resonances, we investigate non-equilibrium dynamics of Qa = Qb = 0 nematic order and its association with both charge density wave (CDW) order and lattice dynamics in La1.65Eu0.2Sr0.15CuO4. In contrast to the slow lattice dynamics probed at the apical oxygen K resonance, fast nematicity dynamics are observed at the Cu L3 and planar oxygen K resonances. The temperature dependence of the nematicity dynamics is correlated with the onset of CDW order. These findings unambiguously indicate that the CDW phase, typically evidenced by translational symmetry breaking, includes a significant electronic nematic component.Comment: 16 pages, 4 figure

One-Body Capillary Plasma Source for Plasma Accelerator Research at e-LABs

We report on the development of a compact, gas-filled capillary plasma source for plasma accelerator applications. The one-body sapphire capillary was created through a diamond machining technique, which enabled a straightforward and efficient manufacturing process. The effectiveness of the capillary as a plasma acceleration source was investigated through laser wakefield acceleration experiments with a helium-filled gas cell, resulting in the production of stable electron beams of 200 MeV. Discharge capillary plasma was generated using a pulsed, high-voltage system for potential use as an active plasma lens. A peak current of 140 A, corresponding to a focusing gradient of 97 T/m, was observed at a voltage of 10 kV. These results demonstrate the potential utility of the developed capillary plasma source in plasma accelerator research using electron beams from a photocathode gun

In Vivo Animal Study of a Highly Viscous N-butyl Cyanoacrylate Medical Adhesive for Intravenous Embolization

N-butyl cyanoacrylate (NBCA) is a liquid monomer that undergoes an exothermic polymerization reaction to form a solid upon initiation with hydroxyl anions. Recently, EGpresto, a highly viscous NBCA-based adhesive, has been developed for vascular-occlusion purposes. In this study, we investigated the heat of polymerization of EGpresto and compared the results with those of a low-viscosity NBCA glue. Results show that EGpresto exhibited a lower heat of polymerization (64 ± 7 °C vs. 34 ± 1 °C). This was due to its high viscosity, which resulted in a delayed polymerization time. To investigate the efficacy and safety of EGpresto for intravenous embolization, a 14 d in vivo animal test was conducted using three pigs. Five cc of EGpresto was injected into the epigastric vein of each animal. Complete postoperative vein occlusion was confirmed at 7 and 14 d by ultrasonographic visualization. After the animals were sacrificed, the operated and unoperated veins were exposed, and the injected adhesive was found without migration. During the histology, the injected adhesive was not found in the inner or outer vein walls, and the immune reactions seemed to be the only foreign-body reaction, showing that EGpresto is a non-toxic and safe intravascular embolic agent

Scalable terahertz generation by large-area optical rectification at 80 TW laser power

We demonstrate high-energy terahertz generation from a large-aperture (75-mm diameter) lithium niobate wafer by using a femtosecond laser with energy up to 2 J. This scheme utilizes optical rectification in a bulk lithium niobate crystal, where most terahertz energy is emitted from a thin layer of the rear surface. Despite its simple setup, this scheme can yield 0.19 mJ of terahertz energy with laser-toterahertz conversion efficiencies of ∼10−4, about 3 times better than ZnTe when pumped at 800 nm. The experimental setup is upscalable for multimillijoule terahertz generation with petawatt laser pumping. © 2019 Optical Society of America11sciescopu

Electron density characterization of inductively-coupled argon plasmas by the terahertz time-domain spectroscopy

Inductively-coupled plasmas (ICP) in the high electron density regime of the order of 1013 cm-3 are generated and their electron density characteristics are investigated by the terahertz time-domain spectroscopy (THz-TDS) method. In this experiment, the plasma was produced by RF (13.56 MHz) with an applied RF power of 300-550 W and the argon gas pressure was in the range of 0.3-1.1 Torr. We generated the THz wave by focusing a femtosecond laser pulse in air with a DC electric field. As a plasma diagnostic tool, the THz-TDS method is found to successfully provide the plasma density information in the high-density regime, where other available plasma diagnostic tools are very limited. In addition, the analytical model based on the ambipolar diffusion equation is compared with experimental observations to explain the behavior of the electron density in the ICP source, where the plasma density is shown to be related to the applied RF power and gas pressure. The analytical result from the model is found to be in good agreement with the THz-TDS result.clos

Counting DNA molecules on a microchannel surface for quantitative analysis

Microscopic visualization of DNA molecules is a simple, intuitive, and powerful method. Nonetheless, DNA -molecule quantification methods that employ microscopic visualization have not been reported so far. In this study, a new quantitative approach is presented that enables the counting of individual DNA molecules that have been rendered visible by fluorescence microscopy. Toward this, a microfluidic device was employed that directed DNA molecules into microchannels and deposited the molecules onto a positively charged surface. This micro -fluidic device had a vertically tapered channel inlet structure that prevented the accumulation of excess DNA molecules in the channel inlet while creating a tapering flow, thereby ensuring the even distribution of the DNA molecules in the microchannels. The channel heights and the density of positive charges on the surface were optimized for analysis. The linearity of this method with respect to the determination of the concentration of DNA in solutions was subsequently determined. The limit of detection was 0.48 fg/mu L, which corresponds to 64 molecules of 7.25 kbp DNA in 1 mu L of sample. This quantitative approach was finally used to count two types of plasmids co-transformed in an E. coli cell; a measurement that is typically considered challenging with gel electrophoresis.N

4D Visualization of a Nonthermal Coherent Magnon in a Laser Heated Lattice by an X-ray Free Electron Laser

Ultrafast optical manipulation of magnetic phenomena is an exciting achievement of mankind, expanding one's horizon of knowledge toward the functional nonequilibrium states. The dynamics acting on an extremely short timescale push the detection limits that reveal fascinating light-matter interactions for nonthermal creation of effective magnetic fields. While some cases are benchmarked by emergent transient behaviors, otherwise identifying the nonthermal effects remains challenging. Here, a femtosecond time-resolved resonant magnetic X-ray diffraction experiment is introduced, which uses an X-ray free-electron laser (XFEL) to distinguish between the effective field and the photoinduced thermal effect. It is observed that a multiferroic Y-type hexaferrite exhibits magnetic Bragg peak intensity oscillations manifesting entangled antiferromagnetic (AFM) and ferromagnetic (FM) Fourier components of a coherent AFM magnon. The magnon trajectory constructed in 3D space and time domains is decisive to evince ultrafast field formation preceding the lattice thermalization. A remarkable impact of photoexcitation across the electronic bandgap is directly unraveled, amplifying the photomagnetic coupling that is one of the highest among AFM dielectrics. Leveraging the above-bandgap photoexcitation, this energy-efficient optical process further suggests a novel photomagnetic control of ferroelectricity in multiferroics